Mounting of playground appliance



March 31, 1959 HARRISON lll 2,879,995

MOUNTING OF PLAYGROUND APPLIANCE Filed March 16, 1956 WHHHHWHM H'Hm/EA/Tm: LEE HARE/510M122,

United States Patent i 2,879,995 MOUNTING or PLAYGROUND APPLIANCE LeeHarrison nrneueviue, 111.

Application March 16, 1956, Serial No. 571,955

' 1 Claims. (Cl. 272-30 The present invention relates to a mounting fora play ground appliance and for the playground appliance itself. Theappliance is in the nature of a merry-go-round, but it has, in additionto the rotary operation, the function of providing a compound rollingundulatory motion.

The appliance consists of a column or base which has a concave'bearingelement therein. This bearing device includes-a generally hemisphericalsocket at its lowest end, aconicalwall surface flaring outwardly fromthe upper part of the hemispherical socket, and a cylindrical or conicalwall surface extending upwardly from the top of the first-conicalsurface. Into the foregoing concave bearing element there fits a shaftor positive bearing element. It has a spherical portion at its bottomthat can bear in the socket portion at the lowest part of the concavepart, a conical section above the spherical section which has a lesserangle of flare than the intermediate section on the support, and a topconical or frusto-conical part. The top part is at such an angle as tohave line engagement with the top section of the concave bearing elementwhen there is line support between the intermediate section of the shaftand the intermediate conical section of the hearing.

The shaft can support at its top a table or other section upon whichpersons or other objects can ride or stand, either at the center or atthe periphery as the case may be.

There have heretofore been various types of rotary apparatus of thiskind, of which the merry-go-round is the most familiar. The presentinvention, however, differs in that it provides the spherical surfacewhich can take the first part of the load, as will appear, coupled withthe two conical. surfaces that have rolling inter-engagement with linecontacts. This gives a different kind of a mo tion than that heretoforeobtained. But more especially it gives its particular kind of motionwith a minimum number of wearing parts, and yet with a minimum ofservice required for the parts. In the particular design the bearingparts are covered so as to keep out dirt, to keep in lubrication, andespecially so as to keep children from getting their arms and legsinvolved with the bearing parts.

The action of this appliance can greatly aid in the development ofmuscles and -muscular coordination, as well as in providing exercise.The appliance is safe, yet movable; it is self-contained andself-controlled, durable and yet challenging and interesting to theusers. In some sizes it can be made into apparatus like merry-goroundsand see-saws, to be employed in playgrounds. In other sizes it may bemade small enough so that the user may stand upon it at the center, andoperate it for strengthening ankles and the lower leg muscles. Inappropriate size it may be used in rehabilitation centers for itsparticular value in connection with leg exercising. In miniature sizesit may be used in toys. Particular types of appliances used on the tablewill vary with the choice of the user, but it is immediatelycontemplated that seats or grab-bars may be placed on the larger sizes,and foot 2,879,995 Patented Mar. 31, 1959 supports may be used on thesmaller sizes, with or without means by which the user may hold himselfagainst falling off the appliance.

In the drawing:

Figure 1 is an elevation of the appliance, broken away somewhat toreduce its height; and

Figure 2 is a diametrical, vertical section through the upper parts ofthe appliance.

The appliance comprises three main parts: a socket or concave bearing 5,a shaft or convex element 6, and a table or like object support 7.

The lower or concave part 5 of the device may include some appropriatebase 8, with a column 9 of suitable character rising therefrom. Needlessto say the choice of means to support the bearing parts of thisappliance may be varied widely within the skill of those in the art.

At its upper end the column 9 has a socket 10 generally of hemisphericalshape, usually with a cylindrical wall rising some distance above thehemispherical portion for a purpose to appear, and also usually with acircular recess or well 11, in the bottom for a purpose to appear.

" Above the socket 10, and flaring outwardly from the an apex.

upper edge of the circular wall, there is a frusto-conicalbearing wallsurface 13, here illustrated as having a flaring angle of about 45degrees. The wall surface 13 is formed from the center of thehemispherical socket 10 as This surface 13 has a base 14, and issurmounted by an additional wall surface 15, that is illustrated asvertical. need to be vertical but for simplicity of manufacture, shouldnot be reentrant towards the top. On the other hand, the circular wallsurface 15 should not flare outwardly at a great angle, because it isdesigned to resist lateral movement of the shaft, as will be described.Above thecylindrical wall surface 15, the bearing element flaresdownwardly and outwardly in a wall 16, the upper surface of which ismade as a portion of a sphere struck about the center of a hemisphericalcenter socket 10.

The shaft or convex portion 6 of the support includes a lowest sphericalpart 17, that is adapted to' fit and bear in the hemispherical socket10. An annular recess 18 around the lower part of the spherical part 17,receives a ball bearing 181 that can travel around the well 11. Abovethe spherical part 17, the shaft is necked-in somewhat at 19, and thenis formed with an integral conical part 20 formed with the center of thehemispherical part 18 as an apex, and a base 21. This conical part ofthe shaft has an angle from the apex which is less than the angle offlare of the socket bearing surface 13, for a purpose to appear. It hasa length such that thedistance along it from the apex to the base 21equals the distance conical section 23 has its base coinciding with thebase 21 of the section 20; and it converges upwardly therefrom. Thearrangement described is such that, when the spherical part 17 rests inthe socket 10, the frusto-conical surfaces 20 and 13, and the circularsurfaces 23 and 15 will have line contact.

Above section 23 there is formed a skirt 25 overlying the portion 16.The skirt 25 should at least overlap the portion 16 at all times, sothat persons may not get parts of their bodies into movable parts of thesupport.

The shaft portion also has the table or object support 7 mounted on it.As heretofore noticed, the table 7 may extend outwardly like amerry-go-round so that persons can ride on its periphery; or if thedevice be of smaller size, the table 7 may be provided with suitablefootreceiving parts so that the person may stand upon it.

In using the device it will be set up as illustrated-in This last wallsurface 15 does not 3 the drawings. If necessary, lubricants may besupplied into the bearing support socket 5. It will be seen that theupper table and shaft parts 6 and 7 may be lifted off of or placed intothe lower socket part 5, with no difficulty.

Normally, the device will fall to one side or the other and so assumes aposition as indicated in the drawings, in which there is linecontact inthe two conical portions and 23 of the shaft 6 with the correspondingportions 13 and 15 of the socketS, and so that the spherical portion 17bears in the spherical socket 10. From such position the table 21 may berotated about its upright center axis. As it is rotated it will trackaround the inside conical surfaces 13 and 15, with a compound motionsomewhat like a planetary. This will cause the table to roll or rotateabout its center at the same time its center vertical axis moves in aconical pattern. Consequently, a particular point on the periphery oftable 7 will move up and down at the same time it is moving around thevertical axis.

In this operation, the primary vertical load is taken on the surface 13,while the lower spherical parts assume the rest of the vertical load andalso act to prevent the device from coming apart. In other words, theperipheral downward load on the lowest part of the table 7 viewed in theplane of Figure 2, tends to rock the bearing about a point somewhere inthe conical surfaces 20, and thereby tends to cause the lower sphericalpart 17 to move upwardly and to theright in the figure. The depth of thesocket portion 10, including its upper cylindrical part, is snfficientto prevent this from happening. Therefore, the primary function of thelower spherical part is to keep such lateral forces from causing thetable part to separate away from the support part and to do so withoutadding an objectionable amount of friction or of wearing parts to theappliance.

The upper cylindrical surface 15 also aids in keeping the shaft 6 andtable 7 from coming out of the socket 5. Centrifugal or other forcecomponents leftward in Figure 2 tend to move the shaft 6 leftward. It isprevented from slipping up the surface 13 and out of the socket by thewall 15 acting against the shaft part 23. That is the reason for makingthe wall 15 without outward flare. It can converge upwardly, but thatadds manufacturing difficulty.

Preferably the table and its assembly is of sufficient weight that whena user tries to mount the upper part of the table the .table will rollaround to bring such part down, rather than hopping across, withoutcontinuous bearing contact of the conical surface. The ball 181 may beused to limit movement of the table to a rotative movement around thecenter vertical axis, without direct rocking movement from side to side.

The operation of the device is performed by shifting of weight from oneside to the other and can be accomplished by two persons (or more) usinga pumping action or by one person standing near the center of the discand shifting his weight from one side to the other.

. What is claimed is:

1. In an appliance of the kind described; a base having a bearingtherein, the bearing having a socket at the lower part that .is in theform of an inverted portion of a sphere with cylindrical wallsupstanding from the spherical portion; a frusto-conical wall projectingupwardly and outwardly from the top of the cylindrical wall, anadditional circular wall projecting upwardly from the top of thefrusto-conical wall; a shaft having a spherically shaped bottom partcomplementary to the spherical portion of the socket, .a frusto-conicalpart extending outwardly from the bottom part to the top of thefrusto-conica'l wall, the sperical bearing and the sperical shaft bottombeing formed about the same center, which center is the apex of thefrusto-conical wall and the frusto-conical part of the shaft; thefrusto-conical part of the shaft having a smaller base diameter thanthat of the corresponding bearing wall, so that the former may rollaround within the latter; the shaft having an additional circular partabove the frusto-conical part that rolls in the additional circular wallprojecting upwardly from the frusto-conical wall; and means on the shaftto receive and support an object to ride the appliance. V,

2. The appliance of claim 1, wherein the additional circular part on theshaft has a frusto-conical shape that is inverted with respect to thepreviously-mentioned frusto-conical part.

3. The appliance of claim 1, wherein the cylindrical wall above thesocket extends upwardly to approximately the top of the spherical shaftpart, so that the shaft cannot be accidently bounced from the socket,but may be lifted therefrom.

4. The appliance of claim 1, wherein the shaft is necked in adjacent tothe junction of the sperical and conical parts, so as to be clear of thehearing at its intersection of the cylindrical and conical walls.

5. The appliance of claim 1, wherein there is a shield on the shaft partthat projects outwardly over and downwardly overlies the uppermost partof the base, the shield having a size suflicient to overlie the base allaround, at any operating position of the shaft in the bearing.

6. The appliance of claim 1, wherein the socket has a lower circularrecess in it, and the spherical shaft part has a smaller circular recessin its bottom part, with a ball bearing in said recesses, the wall ofthe socket recess bearing on the outer side of the ball bearing and thewall of the recess in the shaft part bearing on the inner side of theball.

7. In a device of the kind described, a base, a shaft mounted in saidbase for limited universal movement, said base and shaft havingcomplementary engaging con: cave and convex spherical surfaces,respectively, complementary engaging concave and convex frusto-conicalsurfaces, concentric with the spherical surfaces respectively, andcomplementary engaging concave and convex cylindrical surfaces,respectively, the convex surfaces having their frusto-conical andcylindrical surfaces of smaller diameter than the corresponding concavesurfaces.

References Cited in the file of this patent UNITED STATES PATENTS

